Apyrase-mediated amplification of secretory IgA promotes intestinal homeostasis

Secretory IgA (SIgA) interaction with commensal bacteria regulates the composition and function of the microbiota, contributing to gut ecosystem homeostasis. However, mechanisms regulating the reciprocal control of microbiota and SIgA are not defined. Bacteria-derived ATP limits T follicular helper (Tfh) cells activity in the Peyer's patches (PPs) of the small intestine via the P2X7 receptor and thereby SIgA generation. Here we show that inhibition of bacteria derived ATP signaling by delivery of the ATP-degrading enzyme apyrase to the intestine results in the amplification of the SIgA repertoire. The enhanced breadth of SIgA in mice colonized with apyrase-releasing E. coli conditioned topographical distribution of bacteria and expression of genes involved in metabolic versus immune functions in the intestinal epithelium. SIgA mediated conditioning of bacteria and enterocyte function was also reflected by selective differences in nutrients absorption in mice colonized with apyrase expressing bacteria. Hydrolysis of bacteria derived ATP was particularly helpful in restoring intestinal homeostasis via SIgA in antibiotics induced dysbiosis. Administration of apyrase expressing bacteria attenuated intestinal barrier impairment, glucose metabolism perturbation and susceptibility to infection by enteric pathogens induced by antibiotic treatments. Therefore, microbiota derived ATP regulates SIgA, and amplification of SIgA response by apyrase can be leveraged to restore intestinal fitness in dysbiotic conditions.